A variable-mass frame for flat structures

Abstract: The variable-mass frame for flat structures has a knot element (1) utilizing four arms (2) serially hinged one to another by interaction of respective crown wheels (22) exhibited by the arms (2) at one end (21), at which one end (21) the arms (2) are constrained one to another by a plate (3) exhibiting four pivots (31) defining four rotation axes (A1, A2, A3, A4) for the crown wheels (22); the surface mass of the knot element (1) being varied by nearing or distancing free ends (23) of the arms, which free ends (23) are opposite to said first ends (21).

Description: The invention relates to a variable-mass frame for flat structures utilizable in the realisation of planar structures such as, for example, plinths, panels for false ceilings, false walls and the like. A special application of the invention relates to the erection of stands such as those used in trade fairs and pavilions, or show and exposition areas of various types, where a variable-extension floor or wall structure is required, variable according to the space afforded to the stand. At present, for the erection of such structures tube or other metal parts are used, which are associated one to another such as to create mechanically resistent frames able to support the flat structures. The tubes or other metal parts have variable length and diameter according to the dimensions and type of structure to be erected, and are generally associated one part to another at knot intersections, whereat they are secured by joints. The joints are usually of the friction type, utilizing clamps of various kinds to fasten the tube or other part, and sometimes are joints between L-shaped ends of first tubes or the like inserted in corresponding complementary seats afforded by second tubes or the like. The knots are in effect the basic elements of grids which constitute the rigid support connections of the flat structures. A fundamental requisite of such structures is that they are easy or in any case fast to assemble, provide a sturdy final erection, and are also easy and fast to disassemble, since normally such structures are utilized for short periods of time and then reutilized on further occasions. Furthermore, such structures must be easily adaptable to whatever space is afforded to the exhibitor by the fair organizers. Prior-art structures, using clamped joints or the like, give rise to problematic erection operations, since generally the clamps are tightened on the tubes by means of bolts, which take considerable time to apply. In frames utilizing the above-mentioned L-shaped ends, one drawback is that frequently the mechanical stress they are subjected to is more than they can bear. The aim of the present invention is thus to obviate the above-described drawbacks by providing a collapsible-mass frame for flat structures, which utilizes as a knot element four hinged arms, according to claim 1. Further characteristics and advantages of the present invention will better emerge from the detailed description that follows, of an embodiment of the invention, illustrated in the form of a non-limiting example in the accompanying drawings, in which: figures 1 and 2 are a plan view from above of an embodiment of the knot element of the invention, respectively in a minimum-mass configuration and a maximum-mass configuration, in which a plate constituting means for constraining the knot is respectively partially removed and fully removed; figure 3 is a plan view from above, with some parts removed better to evidence others, and with one detail enlarged and shown in inset, of an embodiment of an arm constituting a component of a knot element according to the invention, bearing at one end a rigid connection element; figures 4, 5 and 6 show respectively a plan view from above, in section according to line V-V of figure 4 and a frontal side view of an embodiment of a plate defining constraining means for the present invention; figure 7 is a frontal view of an embodiment of a pivot utilizable in the invention; figure 8 is a partial frontal view, with some parts removed and others shown in section, of a knot element realised according to the invention and associated to a flat structure. With reference to the figures, a variable-mass frame for flat structures is of the type utilizable for supporting flat structures such as plinths, panels for false ceilings, walls and the like: figure 8 shows an example of a flat structure of this type in the guise of a plinth 4 resting on a lower surface S which might be the ground. The frame is constituted by one or more knot elements 1 which are associated one to another to realize a grid. In the examples provided in the figures, the frame has been schematically represented by one only knot element 1. The knot element 1 comprises four serially-hinged arms 2, each of which exhibits at one end a portion of cylinder 21 provided with a cog wheel 22 exhibiting external cogs forming an external cogged section having an axis which is parallel to the axis X of the cylinder portion 21. Means for constraining the cog wheels 22 are constituted by at least one plate 3 exhibiting four pivots 31 functioning as four rotation axes A1, A2, A3, A4 coinciding with the axes X of the cylinder portion 21 of each arm 2. The pivots 31 are arranged at the four vertices of a square Q of a side L equal to double a value of radius R22 of the base circle of the cogged section of cylinder, such as to enable the arms 2 to be positioned by means of a rotation of the said arms 2 at the serially enmeshed cog wheels 22 in various configurations corresponding to different surface masses of the knot element 1. Figure 1 and figure 2 show respectively the minimum and maximum mass configurations of the knot element 1, which configurations are obtainable by rotating at least one arm 2: since the four arms 2 are hinged in series, they move at the same time, two of them in an anticlockwise direction and the other two in a clockwise direction, as indicated in figure 2 by arrows F. Thus, by rotating an arm 2 through an angle alpha (see figure 2) equal to 45 degrees in relation to an ideal axis Z (parallel to the arms 2 when in a position of minimum mass and equidistanced from axis Z when in a position of maximum mass and in effect the bisector of the angle comprised between two fully-distanced arms 2), the knot element 1 passes from a position of minimum mass to one of maximum mass. The means of constraining can be constituted, as shown in the figures, by two plates 3, each of which affords four holes 30 arrangeed at the four vertices of the abovementioned square Q. The holes are seats for the pivots 31. The plates 3 can be associated parallel one to another and perpendicular to the rotation axes A1, A2, A3 and A4 such as to close, at least partially, the cog wheels 22. Further, the plates 3 can exhibit a fifth hole, centrally disposed on a diagonal of the square Q at a distance from the holes 30 which is not less than the radius T22 of the addendum circle of the cog wheels 22, such as to define a seat for a fifth pivot 35 projecting perpendicularly from the two plates 3 by variable distances in order to permit of regulating a height of the knot element 1 in relation to a surface S on which the knot element 1 can be rested. In figure 8 the hole 32 is threaded and the fifth pivot 35 exhibits a supplementary thread such that the knot element can be height-adjusted in relation to the surface S. For effecting the height-regulation, the pivot 35 is provided at its ends with plates 38, 38a, a first of which 38 strikes against the plinth 4 and a second of which contacts the surface S. Figure 3 shows how each cog wheel 22 is asymmetrical with respect to a median longitudinal axis Y of the arms 2 in order to enable the cog wheels 22 to enmesh in configurations of the knot element 1 where the four arms 2 are parallel one to another, which is to say the minimum mass configuration of figure 1. In the non-limiting examples, internally of the cog wheels 22 the arms 2 exhibit a plurality of portions 24 projecting towards the cylinder axis 21, thus defining a cylindrical hub X in which the pivots 31 are inserted and by which the pivots 31 are axially guided. The pivots 31 can be made as illustrated in figure 7, with a diameter central section M31 which is greater than the diameter of the holes 30 exhibited by the plate 3 and end diameter sections D31 which are smaller and exhibit throats 39 to receive striker rings. Said striker rings would be inserted once the arms 2 are at least partially closed between the plates 3. Figure 3 shows a rigid extension element 29 attached to a free end 23 of an arm 2. The free end 23 is conformed such as to afford a seat for said extension element 29, which might be a tube or the like, so that an entire frame of desired dimensions can be assembled. In figure 3, by way of example, the element is a tube keyed and bolted on the arm 2, with the bolt 28 or rivet being inserted in seats 27, 26 provided on the arm 2 and the tube. In figure 3 there is more than one seat 26 provided on the tube 29 to offer a variety of fixing positions.

Claims: A variable-mass frame for flat structures utilizable in the realisation of flat structures such as, for example, plinths, panels for false ceilings, false walls and the like, characterised in that it comprises one or more knot elements (1), each of which comprises: four arms (2), each of which exhibits a portion of cylinder (21) at one end, which portion of cylinder (21) has an external cogged section having an axis which is parallel to an axis (X) of the cylinder portion (21); means for constraining the ends of the arms comprising at least one plate (3) with four parallel pivots (A1, A2, A3, A4) the axes of which are oriented perpendicularly to the plate, each pivot coinciding with one respective axis (X) of said arms (2); the four pivots being situated at the four vertices of a square (Q) having side lengths (L) equal to double the radius (R22) of the cogged section of cylinder, such that the arms (2) can be rotated about said pivot axes, the four cogged portions reciprocally and serially enmeshed, allowing different orientations of the arms to be achieved. A variable-mass frame for flat structures as in claim 1, characterised in that the means for constraining the ends of the arms are constituted by two plates (3) each provided with four holes (30) arranged at the four vertices of the square (Q) and functioning as seats for receiving said pivots (31); said plates (3) being associable and parallel one to another and being perpendicular to the rotation axes (A1, A2, A3, A4) such as at least partially to enclose the cogged sections of cylinder. A variable-mass frame for flat structures as in claim 1, characterised in that the means for constraining the ends of the arms are constituted by two plates (3), each of which is provided with four holes (30) arranged at the vertices of the square (Q), which holes (30) constitute seats for receiving the pivots (31), and by a fifth hole (32), centrally situated, arranged on a diagonal of the square (Q) at a distance from the four holes (30) which is not less than the radius (T22) of an addendum circle of the cogged sections of cylinder which fifth hole (32) provides a seat for a fifth pivot (35); said plates (3) being associable perpendicularly arranged in relation to the rotation axes (A1, A2, A3, A4) and being distanced one from another by a lesser distance than a length of the fifth pivot (35) such as at least partially to enclose the cogged sections of cylinder, so that the fifth pivot (35) projects from at least one of the fifth holes (32) and perpendicularly from the plates (3) by variable distances, such as to permit of varying a distance of the knot element (1) from a rest surface (S) of the knot element (1). A variable-mass frame for flat structures as in claim 1, characterised in that the cogged section of cylinder is asymmetrical in relation to a median longitudinal axis (Y) of the arms (2) such as to permit of enmeshing the cogged sections of cylinder in a minimum configuration whereat the four arms (2) are parallel one to another. A variable-mass frame for flat structures as in claim 1, characterised in that the arms (2) exhibit internally of the cogged sections of cylinder a plurality of portions (24) projecting towards the axis (X) of the cylinder portion (21), such as to give rise to a hub (K) in which the pivots (31) can be inserted.

Inventors: FERRI STEFANO, FOLLI ALESSANDRO, FERRI, STEFANO, FOLLI, ALESSANDRO
Applicants: FERRI STEFANO, FERRI, STEFANO
Application year: 1994
Main classification: E04F15
IPC codes: E04B1, E04F15